Process for producing refined sugar



L. c. A. FEURTADO ,1 PROCESS FOR PRODUCING REFIRED SUGAR March 19, 1940.

Filed Aug. 22, 1936 0 mm M: 0 m 5m L E EM F H E 6 Y DO B R 0| 0A E ATTORNEYS sider tank.

Patented Mar. 19, 19fl0 PATENT OFFICE.

2,194,195 raocsss roa monnome REFINED SUGAR Leopold Charles Ambrose Feurtado, Kingston, Island of Jamaica, British West Indies Application August 22,1936, Serial No. 97,398

2 Claims.

This invention relates to a process and means for treating the raw juices of the sugar cane and saccharine matter from other sources such as sugar beets, sugar maple, etc., and refers partic- 5 ularly to novel ways and means for clarifying and refining the same in order to produce refined raw sugar, refined table syrup or refined vinegar.

The main object ofmy invention is to manufacture sugar, table syrup or vinegar from sugar i0 cane juice or other saccharine material by means of an inexpensive, simple and expeditious process.

Another object is to utilize a predetermined group of steps, conditions and chemical substances in treating the cane juice and the like so as to obtain uniformly the same dependable clarification of the juice and efiiciency of operation. A further object and particular advantage of the invention is to have'a process of the character indicated which makes it possible by a mere matter of choice during operation, to obtain sugar, table syrup or vinegar as the end product. Yet another object is to introduce a method and means for reducing the percentage of scum produced by causing the same to be more dense and of different character, as well as more completely separated and precipitated than heretofore, and reducing the period of evaporation from crude juice to finished product by free working of the juices and syrups so as to eliminate incrustations in evaporator tubes or vacuum pan coils so as to obtain maximum benefit of the heating employed and reduction of the amount of fuel used, and simultaneously obtain a maxi-.

mum output of sugar, invert sugar or vinegar from the crude juice. r

It is also an object of the invention to use special apparatus adapted for carrying out the 40 process in very eflicient manner'so as to: enhance i Fig. 2 is an enlarged sectional view of -a portion of the same apparatus termedasyphon sub- In these views, the same reference numerals indicate the same or like parts.

With the foregoing objects in view, as well as others not. mentioned, and also in order to eliminate many of the disadvantages inherent in old 5 processes in this art, it is now proposed herein to depart from certain accepted and commonly used principles and methods. Hence, in proceeding to describe my invention, the juice of the sugar cane will be considered as representing a 10 general class .of saccharine substances, and lends itself admirably to a complete disclosure of the invention in practical form.-

'In a sugar mill provided with typical cane crushing machinery, the juice expressed from the i6 cane is thus the raw material with which I shall specifically deal herein, and forms the starting material for the practice of my invention. Therefore, the raw cane juice, as it comes from the" sugar mill I is delivered directly to a container or I0 tank 2 through a pipe 3 and shown in Fig.1.. known'as Feurtados juice purifying tank. The capacity of the same may be 500 to 2.000 imperial gallons or more, or any capacity desired, and the juice is delivered to said purifying tank in its as normally cold condition. When this tank or container is about one quarter full, while the cane juice coming from the mill is actively entering the tank, a chemical mixture termed Nicksilior is] introduced and mixed with the cold juice in such manner as to obtain a churning and conse quently mixing effect, due to the incoming juice by its motion virtually stirring the contents of the .tank. The mixture referred to as entitled Nicksilfor consists of Baceeda glucoside (CuHmOo), 86 in powder form, with or without tannin (CnHmOn), silicious diatoms of about .25 specific gravity, and one or more of the" chemical compounds in the class including phosphoric acid (PzO5)',-hydrochloric acid -(HC 1), sulphuric acid (H2804), sulphurousacid (H2803), citric acid (GH5O4(OH) )3", acetic acid (C2HaO(OH) oxalic acid (HzCaOr), tartaric acid (CrHaOnysodium hydrosulphite (NaI-ISOr), sulphate of alumina (A12(SO 4) 3),, and calcium oxide (CaO), in some- I what varying proportions, according to the chemical constitution of the juice by test. The mentioned Baceeda glucoside may be prepared from the, bark of the bastard cedar tree (Guazuma tomen-tosa) H. B. and K.

I When mixing thementioned "Nicksilfor the same is added to a typical tank of cane juice in the approximate proportions of 400 grains avoirdupois of Baceeda glucoside powder or tannin to silicious diatoms of .25 specific gravity, and 400 grains of phosphoric acid and/or any one of the other compounds of the above mentioned class. This mixture may, of course, be added in any other manner desired and in other proportions, as found preferable in practice.

The cane juice or sugar solution thus initially treated is then passed through a pipe to a juice heater or defecator 4 and passed upward from the same to a group of steam heated clarifiers 6, 6 through a pipe 1 and brought therein to a boiling temperature of about 212 F., more or less, with the result that the natural and other socalled impurities in the juice are rendered insoluble and caused to rise to the surface of the liquid by the combined action of the heat and the added mixture Nicksilfor so as to form a blanket or curd, known in the art as scum. At this stage, every precaution must be taken to allow this scum to boil in or break in with the hot liquid, and must under no circumstances be eliminated, brushed off or skimmed off from the boiling liquid as is ordinarily done in current methods of sugar making.

From this point onward, a slight variation in the subsequent treatment of the boiled juice may be resorted to in accordance with the end product desired, whether this is to be refined raw sugar, table syrup or vinegar.

In the first case, when vacuum pan made raw sugar is to be produced, the heated, that is, boiling liquid is neutralized with lime by treating the same with an aqueous solution or mixture of calcium oxide (CaO) in the form of a lime'cream in the proportion of 2.4 to 3.2 oz. avoirdupois of such cream to each one hundred gallons of juice or sugar solution, more or less, according to actual test with litmus paper or pheno1phthalein,'so that the liquid as a result is left either neutral or only faintly acid in reaction. This liming is, of course, done very cautiously in order to avoid over-liming of the sugar solution, but when this step is completed, the liquid is in proper condition for subsidition for the purpose of completely separating a clear brilliant liquid from the impurities or scum.

'In order to accomplish this, the limed liquid is allowed to descend through pipes 8, 8, etc., intoa group of special containers 9, 9, beneath the clarifiers, known as Feurtados syphon subsiders, one of which is shown more in detail in Fig. 2 with reference to the interior structure thereof, which type of apparatus is' particularly well adapted for the separation of the clear sugar solution from the impurities, which is the next step in the process. The subsiders are interiorly provided with a plurality of spaced, rigid, angular baiiles HI, ID, etc., which control the sedimentation in the apparatus, the baffles being also spaced a short distance above the bottom of the latter. In one end of the subsider is a juice outlet pipe I l to which is attached a ball joint I! by which a float or syphon pipe is connected to pipe ll, while adjacent to the open upper end of pipe I3 is a rigidly attached fioat l4 adapted to support said upper end of pipe l3 just below the surface of the liquid so as to syphon off or decant the clear liquid as far as possible above the bottom liquid which contains the scum or impurities in the form of sediment, and pass the same through pipe H to a storage tank l6 for the clarified juice.

When the treated liquid has been caused to descend into any one or all of said syphon subsiders, it is at most allowed to remain about twenty minutes in order to allow the impurities to settle among the baflies, after which the -clarified solution is decanted as stated, while the sediment is drained off through pipes l5, [5 to filter presses H, I! below the subsiders. The sediment thus received by the filter presses is pressed to expel all remaining crystallizable sugar solution through pipes l8, l8 to a juice receiver I9, whence the juice is passed through a pipe 20 to the storage tank l6 already containing the bulk of the clarified juice. The im purities in the form of press cake are removed from the filter presses and may be used for fertilizer, etc. From the storage tank IS, the clear juice may finally be led by pipe 2| to vacuum pan evaporators 22 and evaporated to dryness and crystallized.

If the sugar to be produced is to be open battery made, the raw cane juice initially treated with the mentioned mixture termed Nicksilfor, is transferred directly to the steam clarifiers 6, 6, and the heat turned on until the juice boils and the scum broken in or boiled in as before, and also limed as described. The heat is discontinued at this stage and the juice delivered, as already mentioned, to the subsider and left therein at maximum, for a period of twenty minutes because the scum subsides rapidly, settling by virtue of the increased specific gravity of the same brought aboutby the addition of the Nicksilfor." The subsequent purification may proceed as previously described-or the liquid may be filtered en masse.

When the clarified juice has been obtained, the same may be evaporated and concentrated into sugar by the known open battery system of boiling sugar, but in general the process up to the concentration of the clarified juice is practically the same as previously described for production of sugar by the vacuum pan method.

In case refined table syrup is to be produced, the initially treated juice, which contains the impurities or scum in boiled-in form, is now treated further to invert the sucrose in solution and thereby prevent sucrose from crystallizing out in the final syrup. This inversion is readily and economically accomplished by adding to the juice, fermented can'juice twenty-four hours old, more or less, in the proportion of ten pounds avoirdupois of such fermented or sour juice to each fifty pounds of initially treated juice, and the resulting liquid boiled in the clarifiers 6, 6 until the density becomes about 25 Baum and the pH 4.5.

When the stated density and concentration have been attained, the acids in the boiling juice are neutralized by liming the latter in similar fashion to that followed in producing the refined sugar. In other words, to each one hundred imperial gallons of boiling juice is added from 2.4 to 3.2 ounces avoirdupois of an aqueous solution of calcium oxide in the form of lime cream, more or less, as indicated by litmus or phenolphthalein test, so as to leave the treated juice neutral or faintly acid in reaction. At this stage, the juice is quite thick, and liming is, of course, done cautiously, to avoid over-liming, as before.

The heat in the clarifiers is discontinued and the thick hot juice either filtered en masse or transferred to the subsiders 9, 9 through pipes 8, 8, etc., and retained in the subsiders a sufficiently long period to allow the coagulated impurities to settle or subside to the partitioned lower portions of the subsiders. It is also possible to simply leave the treated juice undisturbed in the clarifiers, so that the scum settles to the bottom and the clear juice then decanted.

In any case, the resulting thick, clear juice is now ready for evaporation into a refined 5 table syrup consisting substantially of invert sugar (Cal-11206) of any density desired bydrawing the same off through pipes I I, II and 22 from the scum in the subsiders, for example, and evaporating by the triple efiect system in the 10 evaporators 2|, 2|, etc. (without vacuum pan),-

or following the open battery system of boiling sugar as used in the described process of producing sugar. is passed to the filter presses l1, l1 and the juice 15 recovered passed along with the bulk of thejuice produced to the tank 16 and then to the evaporators, while the press cake resulting from the scum is, of course, used for fertilizer as before. The finished syrup or invert sugar is run off from the evaporators to storage tanks and allowed to fine automatically by resting about twenty-four hours preparatory to being run off into containers such as bottles, cans and barrels for the market, and labeled in any manner desired, for

245 example, with the fanciful name or mark Jacana. When cold, the finished juice is not only thick, but clear and brilliant, and preferably has a density of 41.0 Baum and polarization of "10 and over.

30 When the end product is intended to be refined 'vinegar,' the initially treated juice containing the boiled-in scum is boiled in the clarifiers with 1% of hydrochloric acid in order to invert the sugar until a density of about 15 Brix has been attained. Neutralization of the acids present is carried out by liming as previously described, using lime cream in the proportion of 2.4 to 3.2 ounces avoirdupois to each one hundred imperial gallons of hot juice, more 40 or less, as indicated by litmus or phenolphthalein test, and leaving the juice neutral or slightly acid in reaction as before. Heating is then discontinued in the clarifiers, and the hot liquid either left undisturbed to allow the coagulated 5 impurities or scum to settle in the clarifiers, or

else transferred to the subsiders below and the scum allowed to settle therein. In either case, the clear liquid that results, due to the settling of the scum is decanted or syphoned 01! and 5 delivered into vinegar vats (not shown) in a vinegar room adapted for carrying on acetous fermentation for long periods, and in which a temperature ranging from 170 to 195 F. is continuously maintained.

55 When the liquid has cooled to about 120 F.,

it should preferably have a density of about 20 Brix, and at this point it is inoculated with pure yeast and allowed to ferment. In about fortyeight hours, the density will drop to about o Brix, and as the fermentation is continued a long time, this density will remain practically unchanged'for about a month. As the time proceeds toward the end of the second month, acetil fieation proceeds rapidly, and the density will be The scum with its residual juice as low as 4.5 Brix and the specific gravity 1.015, when the solution is practically a finished vinegar.

The vinegar thus produced is then filtered and transferred to bottles, sterilized in hot water, corked and sealed, ready for the market.

Manifestly, variations of the process and means described may be resorted to and features thereof used without others within the scope of the and silicious diatoms a scum which settles when boiled into the mixture, heating the mixture sufiiciently to cause coagulation to occur to form, further treating said mixture by adding a mixture of lime and water in sufiicient quantity to neutralize the acids present, boiling in the scum in the liquid in order to effectively neutralize the acid present and to concentrate said scum, discontinuing the heating so as to allow the'scum to settle to the bottom of the juice, and then decanting the juice above the level of the settled scum in order toobtain a purified juice capable of being worked up at will in conventional manner.

2. The process for purifying raw saccharine juices, which consists in heating in the proportions of about 100 gallons of the raw juice to about the boiling point of water in the presence of about 400 grains avoirdupois of Baceeda glucoside in finely divided form, about 450 grains of silicious diatoms having a specific gravity of 0.25 and about 400 grains of a reagent capable of reacting with the Baceeda glucoside and silicious diatoms so as to coagulate the impurities in said juice into a scum which tends to settle when boiled into the juice, said reagent comprising at least one of a plurality of defecants capable of thus coagulating with the Baceeda glucoside and silicious diatoms to form said settling scum, further treating said juice mixture by adding a mixture of lime and water in sufllcient quantity to neutralize the acids present, boiling in the scum in the liquid in order to effectively neutralize the acid present and to concentrate said scum, discontinuing the heating so as to allow the scum to settle to the bottom of the juice, and then decanting the juice above the level ofthe settled scum in order to obtain a purified juice capable of being worked up at will in conventional manner.

LEOPOLD CHARLES AMBROSE FEURTADO. 

